function get_redirect_url($url){
		$redirect_url = null; 
	 
		$url_parts = @parse_url($url);
		if (!$url_parts) return false;
		if (!isset($url_parts['host'])) return false; //can't process relative URLs
		if (!isset($url_parts['path'])) $url_parts['path'] = '/';
	 
		$sock = fsockopen($url_parts['host'], (isset($url_parts['port']) ? (int)$url_parts['port'] : 80), $errno, $errstr, 30);
		if (!$sock) return false;
	 
		$request = "HEAD " . $url_parts['path'] . (isset($url_parts['query']) ? '?'.$url_parts['query'] : '') . " HTTP/1.1\r\n"; 
		$request .= 'Host: ' . $url_parts['host'] . "\r\n"; 
		$request .= "Connection: Close\r\n\r\n"; 
		fwrite($sock, $request);
		$response = '';
		while(!feof($sock)) $response .= fread($sock, 8192);
		fclose($sock);
	 
		if (preg_match('/^Location: (.+?)$/m', $response, $matches)){
			if ( substr($matches[1], 0, 1) == "/" )
				return $url_parts['scheme'] . "://" . $url_parts['host'] . trim($matches[1]);
			else
				return trim($matches[1]);
	 
		} else {
			return false;
		}
	 
	}

Ben bu fonksiyonu kullanıyorum. php.net den bulmuştum galiba.

$yeni_url = get_redirect_url($url);

şeklinde kullanabilirsin.